Pedicle screws and spinal rods are frequently used to stabilize or re-shape a spine. For the treatment of spondylolisthesis and similar conditions requiring reducing bony structures that are out of position, sometimes pedicle screws are made that have heads that contain internally threaded extension tabs that are longer than the ultimately desired dimensions of the screw head. A setscrew can be engaged with the extension tabs and can be used to urge a spinal rod and a pedicle screw toward each other.